Prayer is a universal religious ritual, even among the secular. Although prayer is assumed to be beneficial, the empirical evidence is sparse. What rigorous research exists, concentrates on prayer’s subjective effects and correlates. There is reason to think that these subjective mechanisms could translate to objective performance, such that praying for an objective outcome might bring about that outcome (without divine intervention) through one or more cognitive mechanisms. The primary aim of this thesis was to examine prayer’s effects on cognitive performance, and the mediating mechanisms that could account for its effects.

In two experiments, one in which prayer content was controlled and another in which participants generated the content, prayer differentially affected anagram performance depending on participants’ supernatural beliefs. Believers performed better after praying than after one of several control manipulations, and the opposite was true for nonbelievers.

Several mechanisms were explored as potential mediators of these effects. In Studies 1 and 2, emotional and arousal accounts of prayer were considered. Study 1 showed that believers who prayed experienced increased arousal and positive affect, but Study 2 did not replicate these effects. Study 2 revealed initial evidence of an alternative attributional account of prayer. Believers who prayed not only performed better on the anagram task, but also reported more internal attributions of control over their performance. However, the results of Studies 3 and 4, which investigated prayer’s effects on attributions of control, in the absence of performance were inconsistent with this account. Study 3 suggested another potential mechanism, that believers who prayed perceived their prayers as more effective in improving their performance. However, expectancy perceptions did not translate into predictions about performance, casting doubt on this account. Study 5 examined two alternative mechanisms; social influence and self-control. Preliminary results did not support a social influence account of prayer. However, results showed initial support for a self-control account of prayer, with prayer increasing the ability to forgo immediate rewards as religiosity increased. Study 6 investigated prayer’s effects on cheating, an activity associated with self-control. Overall, nonbelievers were less inclined to cheat than believers. Prayer acted as a self-control enhancement for believers (but not nonbelievers), decreasing their cheating to the level of nonbelievers.

Despite a number of limitations, most notably the absence evidence for a complete causal model, the six studies together provide a number of basic experimental and correlational findings regarding the relationship between religious belief, prayer, and performance. Future research should investigate the replicability and generalizability of these results.